Patients and MethodsThe subjects in this stucy were 14 healthy acults with normal respiratory function (control group) and 29 patients (patient group) subjected to sagittal osteotomy accompanied by intermaxillary fixation uncer general anesthesia. Measurement items were the presence of nasal breathing and oral breathing, tical volume (VT) in each respiratory route, respiratory minute volume, respiratory rate (RR), enc -tical C02 concentration (EtCO2), and oxygen saturation (SpO2). In the control group, measurements were taken before and after intermaxillary fixation of upper and lower tooth rows by wire ligation. In the patient group, measurements were taken on the cay before surgery, and when the respiratory condition was stabilizedfollowing extubation aftergeneral anesthesia.ResultsThere were no significant cifferences in any of the measurement items before and after intermaxillary fixation both in the control N - N group whose respiratory route before and after intermaxillary fixati
… Moreon was only nasal breathing, and in the control NO- N group whose respiratory routes were nasal and oral breathing before intermaxillary fixation but only nasal breathing after intermaxillary fixation. In the patient group, there were no significant cifferences in any of the measurement items before and after surgery in the patient N-N group whose respiratory route before surgery and aftergeneral anesthesia during intermaxillary fixation was only nasal breathing.In patient NO-N group who showed nasal and oral breathing preoperatively but showed only nasal breathing postoperatively, the tical volume and respiratory minute volume of the nasal breathing (id not change postoperatively. However, since the respiratory volume of the oral breathing cisappearec, the total respiratory volume cecreased significantly postoperatively. The respiratory rate and SpO2 cid not change. EtCO2, however, increasec. In the patient group, we comparatively stucied only N - N and NO-N.There were only a few cases in which the preoperative and postoperative respiratory routes were NO-O (3 case), N- 0(1 case), 0 -N (1 case), and NO-NO (one case).3) 顎間固定後の口呼吸の消失は開口制限によるものと考えられる。3. 顎間固定と手術前後の呼吸機能について1) 手術症例における顎間固定後の呼吸経路は鼻呼吸を主とするものが29例中27例(93.1%)であった。2) 顎間固定後に口呼吸が消失する症例がみられた。3) 顎間固定前、鼻呼吸および口呼吸の両者を呼吸経路にしていた症例では、術中の顎間固定によって全身麻酔後鼻呼吸のみとなり、TVおよびMVの減少とEtCO2の増加が認められた。4) 鼻呼吸経路の閉塞によって口呼吸経路への移行が認められ、鼻呼吸経路の解放により再び鼻呼吸が再開するが、同時に口呼吸も継続して観察された。しかし、SpO2、PaO2およびPaCO2の変動から術直後の鼻閉に関しては注意が必要である。 Less